Three-dimensional printer



FIG. 1 is a front perspective view of the three-dimensional printer showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a left side view thereof; and,

FIG. 6 is a right side view thereof.

The broken lines illustrate unclaimed portions of the three-dimensional printer that form no part of the claimed design. 

CLAIM The ornamental design for a three-dimensional printer, as shown and described. 